Rock 3A DSI ST7701

#21

Please show the original DTS and not the decompiled DTS， and please show the log of “sudo dmesg | grep st7701”

#22

If you are using our official system, the different code style is probably caused by the fact that you haven’t updated rsetup, my code style applies to the current or recent rsetup parsing.

#23 
dmesg | grep st7701
[    9.707897] st7701 fe070000.dsi.0: Looking up VCC-supply from device tree
[    9.707935] st7701 fe070000.dsi.0: Looking up VCC-supply property in node /dsi@fe070000/st7701@0 failed
[    9.707964] st7701 fe070000.dsi.0: supply VCC not found, using dummy regulator
[    9.708176] st7701 fe070000.dsi.0: Looking up IOVCC-supply from device tree
[    9.708210] st7701 fe070000.dsi.0: Looking up IOVCC-supply property in node /dsi@fe070000/st7701@0 failed
[    9.708234] st7701 fe070000.dsi.0: supply IOVCC not found, using dummy regulator
[    9.712135]  st7701_dsi_probe+0x15c/0x160
[    9.712233]  st7701_dsi_driver_init+0x24/0x30

The issue seems to be with the CRTC, but I didn’t think that the connection to the CRTC needed to be explicitly defined in the DTS.

modetest -M rockchip -s 114@0:480x854
             failed to find CRTC for pipe
             failed to create dumb buffer: Invalid argument
#24

The error indicates that you need to fill in the VCC-supply and IOVCC-supply properties， of course, according to the actual hardware circuit diagram.

#25

and you can find circuit diagram in the page https://docs.radxa.com/en/rock3/rock3a/getting-started/download

#26

Hi, thanks for your help
I managed to activate the display by switching to vp0, but the resolution and timings do not match.
As far as I understand, for the 7701 driver I cannot change the timings and resolution in dts.
It turns out that I need to make a patch on the kernel each time while I select the parameters, or are there easier ways?

#27

for resolution, please try properties panel-width-mm and panel-height-mm

#28

or, width_mm and height_mm